Declaration And Access Control — Part 1 MCQs with Explanations

var-args = variable number of arguments = 0 or many void add(Integer... args){} is correct IF made "static" as it's called from a static context: main(). Var-args can be of both object(eg Integer) and primitive(eg int) types. static void add(int... args, int y){} is correct IF its parameters' order is reversed. If a method has both var-arg(0 or MAX 1) + non-var-args(0 or more) parameters then the var-arg parameter MUST come LAST! static void add(int args...){} : "..." must come after the type of the var-arg parameter, not after its name static void add(int[]... args){} : for this to be a correct declaration then add() should have been called something like this: "add(arr);" or "add(arr, arr);" where "arr" could be defined as "int[] arr = new int[5];" static void add(int...args){} is a valid way to define var-args (there is no need to have any space between "..." and the type and name of the var-arg param)

Implicit super constructor Base is not visible, must explicitly invoke another constructor.

static methods can't invoke 'this'.

static methods cannot make references to non-static variables.

As soon as the class are loaded static variables are initialized first. To initialize it demo must be called first then then static block executes and then main method is called.

Think of a package like a folder or a directory on your computer. What do you usually put in a folder? Files! In Java, packages help us organize our code. Classes and Interfaces are both types of "files" in Java. So, a package can contain both. Option A is partially correct (Classes), but it's not the whole story. Option B is also partially correct (Interfaces), but it's also not the complete picture. Option C and Option E are incorrect because "Editing tools" are not stored within the Java package. Option D is the most accurate. Therefore, the correct answer is D: Classes and Interfaces.

This will compile and print "Hello". The entry point for a standalone java program is the main method of the class that is being run. The java run-time system will look for that method in class Test and find that it should have such a method. It does not matter whether it is defined in the class itself or is inherited from a parent class.

First execute static block, then statement block and then constructor.

Java pass reference as value. passing the object reference, and not the actual object itself. Simply reassigning to the parameter used to pass the value into the method will do nothing, because the parameter is essentially a local variable.

A variable declared in a static initializer is not accessible outside its enclosing block.

All static blocks execute first then blocks and constructor. Blocks and constructor executes (super class block then super class constructor, sub class block then sub class constructor). Sequence for static blocks is super class first then sub class. Sequence for blocks is super class first then sub class.

Outer class can only declare public , abstract and final. Illegal modifier for the class Test; only public, abstract & final are permitted.

Static members are common for all objects, where as ‘this’ refer to a particular object. so we cant use ‘this’ operator in the static methods.

While compiling the Test class, the compilation error occurs implying that the final parameter x cannot be assigned a value. Therefore the option B is correct and remaining options are incorrect.

package-private is the correct answer to “What is the default access modifier for class members in Java if no access modifier is specified”. This question is standard in competitive examination syllabi for Declaration And Access Control.

protected is the correct answer to “Which access modifier restricts a class member's visibility only to the same class and its subclasses”. This question is standard in competitive examination syllabi for Declaration And Access Control.

final is the correct answer to “What keyword is used to declare a constant in Java, which is implicitly final and static”. This question is standard in competitive examination syllabi for Declaration And Access Control.

public is the correct answer to “Which of the following access modifiers allows access to a class member from any class in any package”. This question is standard in competitive examination syllabi for Declaration And Access Control.

package-private is the correct answer to “What is the access level of a class member with no access modifier specified in Java”. This question is standard in competitive examination syllabi for Declaration And Access Control.

package-private is the correct answer to “In Java, which access modifier allows a method or variable to be accessed within the same package only”. This question is standard in competitive examination syllabi for Declaration And Access Control.

final is the correct answer to “Which keyword is used to explicitly specify that a method cannot be overridden in a subclass”. This question is standard in competitive examination syllabi for Declaration And Access Control.

package-private is the correct answer to “What is the default access modifier for a class in Java if no access modifier is specified”. This question is standard in competitive examination syllabi for Declaration And Access Control.

package-private is the correct answer to “Which access modifier allows a class member to be accessed only within its own class and package”. This question is standard in competitive examination syllabi for Declaration And Access Control.

public is the correct answer to “In Java, which access modifier allows a class member to be accessed from anywhere in the code”. This question is standard in competitive examination syllabi for Declaration And Access Control.

static is the correct answer to “What keyword is used to declare a method that can be called without creating an instance of the class”. This question is standard in competitive examination syllabi for Declaration And Access Control.

package-private is the correct answer to “Which of the following access modifiers restricts a method or variable's access to the same package only”. This question is standard in competitive examination syllabi for Declaration And Access Control.

It allows access from any class. is the correct answer to “In Java, what is the purpose of the static keyword when applied to a variable”. This question is standard in competitive examination syllabi for Declaration And Access Control.

super is the correct answer to “Which keyword is used to define a superclass's method that is overridden by a subclass method”. This question is standard in competitive examination syllabi for Declaration And Access Control.

private is the correct answer to “What is the access level of a class member declared as private in Java”. This question is standard in competitive examination syllabi for Declaration And Access Control.

protected is the correct answer to “Which access modifier allows a class member to be accessed within the same package and its subclasses”. This question is standard in competitive examination syllabi for Declaration And Access Control.

abstract is the correct answer to “What is the keyword used to declare a class that cannot be instantiated and can only be extended”. This question is standard in competitive examination syllabi for Declaration And Access Control.

private is the correct answer to “In Java, what access modifier is used to specify that a class member can be accessed only within its class”. This question is standard in competitive examination syllabi for Declaration And Access Control.

abstract is the correct answer to “Which of the following is not an access modifier in Java”. This question is standard in competitive examination syllabi for Declaration And Access Control.

public is the correct answer to “What access modifier allows a class member to be accessed from any class in the same package or any subclass”. This question is standard in competitive examination syllabi for Declaration And Access Control.

public is the correct answer to “In Java, which access modifier allows a class member to be accessed from any class, even outside the package”. This question is standard in competitive examination syllabi for Declaration And Access Control.

abstract is the correct answer to “What keyword is used to declare a method that is implemented in a subclass to provide a specific implementation”. This question is standard in competitive examination syllabi for Declaration And Access Control.

It makes the method constant. is the correct answer to “In Java, what is the purpose of the final keyword when applied to a method”. This question is standard in competitive examination syllabi for Declaration And Access Control.

default is the correct answer to “Which access modifier allows a class member to be accessed from any class in the same package but not from outside”. This question is standard in competitive examination syllabi for Declaration And Access Control.

static is the correct answer to “What keyword is used to declare a variable that can be accessed without creating an instance of the class”. This question is standard in competitive examination syllabi for Declaration And Access Control.

protected is the correct answer to “Which access modifier restricts a class member's visibility to only the same class, its package, and subclasses”. This question is standard in competitive examination syllabi for Declaration And Access Control.